EXAM #3 INFOMATION

When stimulating the nerve with a pair of electrical shocks, if the delay between the two shocks is short, the second action potential may be ___________________ than the first.

Smaller

Why does the amplitude of the compound action potential increase between the threshold and maximum stimulus?

More axons pull sodium into the cell

When recording a compound action potential from a nerve, where are the two recording electrodes placed?

both are outside the cell

Which of the following parameters cannot be measured when recording the compound action potential?

resting membrane potential

Measuring refractory periods of nerves involves

adjusting the time interval between two stimuli delivered a short time apart

Putting a nerve is an isotonic potassium chloride solution would be expected to ______________ the nerve fiber.

depolarize

The minimum stimulus necessary to stimulate a maximum response is the ____________________ stimulus.

maximum

True or false? Receptor number in the post-synaptic density is variable

True

Where are the tarsal gland located?

In the eye lids

Target organs for the sympathetic nervous system have...

adrenergic receptors

What receptor do you find on adrenal medullary cells?

Nicotinic receptors

What kind of ion channel is the ionotropic GABA receptor?

Chloride channel

The most common drugs used to treat depression, such a prozac (fluoxetine), act through which neurotransmitter?

Serotonin

Which cranial nerves contain autonomic pre-ganglionic neuronal axons

Oculomotor (III)

Facial (VII)

Glossopharyngeal (IX)

Vagus (X)

Draw a flow chart for the prediction of the three catecholamines including all the intermediates and the rate-limiting enzyme

Tyrosine -- Tyrosine Hydroxylase----->>>> L-dopa --->>>> Dopamine --->>>> norepinephrine ---> epinephrine

The minimum stimulus necessary to stimulate a measurable response is the _____________________ stimulus.

threshold

Sensory pathways that carry information from the fingertip...

have small receptive files and have low levels of convergence

How is the intensity of touch communicated to the cerebral cortex?

varying action potential frequency

The taste blindness tested in lab is an inability to taste certain _________________ compounds.

bitter

Olfactory adaptation is due to

receptor-mediated endocytosis of olfactory receptors

Thermoreceptors are better at telling us about

changes in temperature

True or False? You can hear by getting the skull to vibrate even if the eardrum (tympanic membrane) doesn't vibrate.

True

True or false? Our brain receives a different image from each eye.

True

Parallax is better for depth perception for

close objects

The blind spot is ______________ to the fovea centralis.

medial

True or False? Normally when testing the patellar stretch reflex, there are descending inhibitory inputs from the brain.

True

True or false? EPSPs and IPSPs are graded potentials

True

Internodal region of a myelinated neuron are...

less leaky for potassium

The absolute refractory period is primarily due to the...

voltage-gated sodium channel

The relative refractory period is primarily due to the...

voltage-gates potassium channel

Which type of synapses have more influence on whether or not a post-synaptic cell fires an action potential

axosomatic

Opening of a non-specific cation channel in a resting cell cause...

more sodium to enter the cell than potassium to leave the cell

Neurons carrying pain information to the central nervous system (nociceptors) have a...

thin axon and are unmyelinated

decreasing potassium permeability will cause the cell to

depolarize

A solution containing 200mM permeable solute and 300 mM non-permeable solute would be...

hyperosmotic and isotonic

True or false? A single neuron often releases more than one type of catecholamine

False

True or false? A single neuron only releases one type of neurotransmitter

False

True or false? Adrenergic refers to both epinephrine and norepinephrine

True

True or false? All efferent neurons from the central nervous system release acetylcholine that then bind to nicotinic receptors.

True

True or false? Neuropeptides are usually not released until the presynaptic neuron fires several action potentials in quick succession

True

True or false? Substance P enhances painful stimuli

True

Endogenous opioids are...

inhibitory

In the parasympathetic nervous system, the ____ neuron is longer

postganglionic

Automatic post-ganglionic neurons have ___ on their cell body and dendrites

nicotinic receptors

Endogenous opioids are released in...

axoaxonic synapses

True or false? beta2 adrenergic receptors can be found outside of synapses

true

True or false? some places in the brain do not have a blood-brain barrier

true

True or false? only first order neurons have a receptive feild

false

true or false? both the sympathetic and parasympathetic nervous systems always have some level of activity

true

the blood-brain barrier controls the entry of ___ into the brain

water-soluble substances

pre-ganglionic neurons ___ postganglionic neurons in the automatic nervous system

stimulate

The blood-brain barrier is found...

in the blood vessels throughout the brain

Which diencephalic region helps control the autonomic nervous system?

hypothalamus

Which adrenergic receptor has a low affinity for norepinephrine?

beta2

Which branch of the nervous system tends to have finer control over individual organ systems?

parasympathetic nervous system

lateral inhabitation _____ sensory acuity

increases

The duration of a stimulus can be coded by...

slow-adapting neurons

endogenous opioids are primarily released in...

descending sensory pathways

True or false? sensory pathways that do not code for modality would be useless to the brain

false

In somatic sensation pathways, ___ order neurons cross to the contralateral side of the spinal cord

2nd

The somatosensory cortex is in the ___ lobe

parietal

The lacrimal gland is controlled by the...

parasympathetic nervous system

True or false? tears drain into the nose

true

The conjunctiva is usually

clear

The anterior compartment of the eye is between the..

lens and the cornea

There are no photoreceptors in the...

optic disc

True or false? humans can only detect a very small portion of the electromagnetic spectrum

true

Wavelengths of light that are ___ by an object can be detected by our photoreceptors when we look at the object

reflected

The most refraction of light occurs when light passes through the...

cornea

True or false? The image that focuses on our retina is upside-down and backwards

true

Contraction of the ciliary muscles in the eye causes the suspensory ligaments to..

pull less on lens

The ciliary muscle of the eye is primarily innervated by which branch of the nervous system it?

parasympathetic

The stress response leads to enhanced.

far-vision

Which cells in the retina would light hit first

the ganglion cells

True or false? The fovea centralis is a pit in the retina

True

________________ are active in high light conditions.

cones

When light passes into a slower medium it is bend toward an angle ______________________ to the interface between the media.

perpendicular to the

For near vision...

the ciliary muscles contract and the lens gets fatter

Photopigment is found in the ________________________________ of a photoreceptor.

outer segment

The phosphodiesterase in the photoreceptor that is involved in light signal transduction

converts cGMP into GMP

Lateral inhibition assists in

determining location

True or false? Some sensory pathways do not carry information about modality.

true

Skin receptors for pressure are

slow-adapting

Ethanol...

increases membrane fluidity

Hyaluronic acid is found in

vitreous humor

Greater sensory neuron density leads to ____________________ sensory acuity.

greater

Intensity in the sensory system is coded by

action potential frequency

Which adrenergic receptor causes smooth muscle contraction?

alpha 1

Most post-ganglionic sympathetic neurons release

norepinephrine

The primary hormone released by the adrenal medulla is

epinephrine

Most of the serotonin is the body is found in

digestive tract

Muscarinic receptors are

metabotropic receptors

The autonomic nervous system uses ____________ neurons to get from the central nervous system to the target organ.

2

The NMDA receptor is

a calcium channel

Monoamine oxidase is involved in the degradation of (select all that apply)

epinephrine and norepinephrine

The thicker the axon diameter

the slower potassium leaks out of the cell during an action potential

Opening a chloride channel in a cell that does not regulate chloride would

dampen the depolarizing effect of opening a sodium channel

The highest concentration of voltage-gated sodium channels is in the plasma membrane of

the nodes of Ranvier of mylinated neurons

Action potentials during the relative refractory period

have a lower amplitude than action potentials fired from the resting membrane potential

What protein does calcium bind to in the presynaptic terminal that leads to exocytosis of neurotransmitter?

synaptotagmin